via82xx_modem.c

linux 内核源代码

{
	struct via82xx_modem *chip = ac97->private_data;
	unsigned int xval;
	if(reg == AC97_GPIO_STATUS) {
		outl(val, VIAREG(chip, GPI_STATUS));
		return;
	}	
	xval = !ac97->num ? VIA_REG_AC97_CODEC_ID_PRIMARY : VIA_REG_AC97_CODEC_ID_SECONDARY;
	xval <<= VIA_REG_AC97_CODEC_ID_SHIFT;
	xval |= reg << VIA_REG_AC97_CMD_SHIFT;
	xval |= val << VIA_REG_AC97_DATA_SHIFT;
	snd_via82xx_codec_xwrite(chip, xval);
	snd_via82xx_codec_ready(chip, ac97->num);
}

static unsigned short snd_via82xx_codec_read(struct snd_ac97 *ac97, unsigned short reg)
{
	struct via82xx_modem *chip = ac97->private_data;
	unsigned int xval, val = 0xffff;
	int again = 0;

	xval = ac97->num << VIA_REG_AC97_CODEC_ID_SHIFT;
	xval |= ac97->num ? VIA_REG_AC97_SECONDARY_VALID : VIA_REG_AC97_PRIMARY_VALID;
	xval |= VIA_REG_AC97_READ;
	xval |= (reg & 0x7f) << VIA_REG_AC97_CMD_SHIFT;
      	while (1) {
      		if (again++ > 3) {
			snd_printk(KERN_ERR "codec_read: codec %i is not valid [0x%x]\n",
				   ac97->num, snd_via82xx_codec_xread(chip));
		      	return 0xffff;
		}
		snd_via82xx_codec_xwrite(chip, xval);
		udelay (20);
		if (snd_via82xx_codec_valid(chip, ac97->num) >= 0) {
			udelay(25);
			val = snd_via82xx_codec_xread(chip);
			break;
		}
	}
	return val & 0xffff;
}

static void snd_via82xx_channel_reset(struct via82xx_modem *chip, struct viadev *viadev)
{
	outb(VIA_REG_CTRL_PAUSE | VIA_REG_CTRL_TERMINATE | VIA_REG_CTRL_RESET,
	     VIADEV_REG(viadev, OFFSET_CONTROL));
	inb(VIADEV_REG(viadev, OFFSET_CONTROL));
	udelay(50);
	/* disable interrupts */
	outb(0x00, VIADEV_REG(viadev, OFFSET_CONTROL));
	/* clear interrupts */
	outb(0x03, VIADEV_REG(viadev, OFFSET_STATUS));
	outb(0x00, VIADEV_REG(viadev, OFFSET_TYPE)); /* for via686 */
	// outl(0, VIADEV_REG(viadev, OFFSET_CURR_PTR));
	viadev->lastpos = 0;
}


/*
 *  Interrupt handler
 */

static irqreturn_t snd_via82xx_interrupt(int irq, void *dev_id)
{
	struct via82xx_modem *chip = dev_id;
	unsigned int status;
	unsigned int i;

	status = inl(VIAREG(chip, SGD_SHADOW));
	if (! (status & chip->intr_mask)) {
		return IRQ_NONE;
	}
// _skip_sgd:

	/* check status for each stream */
	spin_lock(&chip->reg_lock);
	for (i = 0; i < chip->num_devs; i++) {
		struct viadev *viadev = &chip->devs[i];
		unsigned char c_status = inb(VIADEV_REG(viadev, OFFSET_STATUS));
		c_status &= (VIA_REG_STAT_EOL|VIA_REG_STAT_FLAG|VIA_REG_STAT_STOPPED);
		if (! c_status)
			continue;
		if (viadev->substream && viadev->running) {
			spin_unlock(&chip->reg_lock);
			snd_pcm_period_elapsed(viadev->substream);
			spin_lock(&chip->reg_lock);
		}
		outb(c_status, VIADEV_REG(viadev, OFFSET_STATUS)); /* ack */
	}
	spin_unlock(&chip->reg_lock);
	return IRQ_HANDLED;
}

/*
 *  PCM callbacks
 */

/*
 * trigger callback
 */
static int snd_via82xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
	struct viadev *viadev = substream->runtime->private_data;
	unsigned char val = 0;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_SUSPEND:
		val |= VIA_REG_CTRL_START;
		viadev->running = 1;
		break;
	case SNDRV_PCM_TRIGGER_STOP:
		val = VIA_REG_CTRL_TERMINATE;
		viadev->running = 0;
		break;
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		val |= VIA_REG_CTRL_PAUSE;
		viadev->running = 0;
		break;
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		viadev->running = 1;
		break;
	default:
		return -EINVAL;
	}
	outb(val, VIADEV_REG(viadev, OFFSET_CONTROL));
	if (cmd == SNDRV_PCM_TRIGGER_STOP)
		snd_via82xx_channel_reset(chip, viadev);
	return 0;
}

/*
 * pointer callbacks
 */

/*
 * calculate the linear position at the given sg-buffer index and the rest count
 */

#define check_invalid_pos(viadev,pos) \
	((pos) < viadev->lastpos && ((pos) >= viadev->bufsize2 ||\
				     viadev->lastpos < viadev->bufsize2))

static inline unsigned int calc_linear_pos(struct viadev *viadev, unsigned int idx,
					   unsigned int count)
{
	unsigned int size, res;

	size = viadev->idx_table[idx].size;
	res = viadev->idx_table[idx].offset + size - count;

	/* check the validity of the calculated position */
	if (size < count) {
		snd_printd(KERN_ERR "invalid via82xx_cur_ptr (size = %d, count = %d)\n",
			   (int)size, (int)count);
		res = viadev->lastpos;
	} else if (check_invalid_pos(viadev, res)) {
#ifdef POINTER_DEBUG
		printk(KERN_DEBUG "fail: idx = %i/%i, lastpos = 0x%x, "
		       "bufsize2 = 0x%x, offsize = 0x%x, size = 0x%x, "
		       "count = 0x%x\n", idx, viadev->tbl_entries, viadev->lastpos,
		       viadev->bufsize2, viadev->idx_table[idx].offset,
		       viadev->idx_table[idx].size, count);
#endif
		if (count && size < count) {
			snd_printd(KERN_ERR "invalid via82xx_cur_ptr, "
				   "using last valid pointer\n");
			res = viadev->lastpos;
		} else {
			if (! count)
				/* bogus count 0 on the DMA boundary? */
				res = viadev->idx_table[idx].offset;
			else
				/* count register returns full size
				 * when end of buffer is reached
				 */
				res = viadev->idx_table[idx].offset + size;
			if (check_invalid_pos(viadev, res)) {
				snd_printd(KERN_ERR "invalid via82xx_cur_ptr (2), "
					   "using last valid pointer\n");
				res = viadev->lastpos;
			}
		}
	}
	viadev->lastpos = res; /* remember the last position */
	if (res >= viadev->bufsize)
		res -= viadev->bufsize;
	return res;
}

/*
 * get the current pointer on via686
 */
static snd_pcm_uframes_t snd_via686_pcm_pointer(struct snd_pcm_substream *substream)
{
	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
	struct viadev *viadev = substream->runtime->private_data;
	unsigned int idx, ptr, count, res;

	snd_assert(viadev->tbl_entries, return 0);
	if (!(inb(VIADEV_REG(viadev, OFFSET_STATUS)) & VIA_REG_STAT_ACTIVE))
		return 0;

	spin_lock(&chip->reg_lock);
	count = inl(VIADEV_REG(viadev, OFFSET_CURR_COUNT)) & 0xffffff;
	/* The via686a does not have the current index register,
	 * so we need to calculate the index from CURR_PTR.
	 */
	ptr = inl(VIADEV_REG(viadev, OFFSET_CURR_PTR));
	if (ptr <= (unsigned int)viadev->table.addr)
		idx = 0;
	else /* CURR_PTR holds the address + 8 */
		idx = ((ptr - (unsigned int)viadev->table.addr) / 8 - 1) %
			viadev->tbl_entries;
	res = calc_linear_pos(viadev, idx, count);
	spin_unlock(&chip->reg_lock);

	return bytes_to_frames(substream->runtime, res);
}

/*
 * hw_params callback:
 * allocate the buffer and build up the buffer description table
 */
static int snd_via82xx_hw_params(struct snd_pcm_substream *substream,
				 struct snd_pcm_hw_params *hw_params)
{
	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
	struct viadev *viadev = substream->runtime->private_data;
	int err;

	err = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
	if (err < 0)
		return err;
	err = build_via_table(viadev, substream, chip->pci,
			      params_periods(hw_params),
			      params_period_bytes(hw_params));
	if (err < 0)
		return err;

	snd_ac97_write(chip->ac97, AC97_LINE1_RATE, params_rate(hw_params));
	snd_ac97_write(chip->ac97, AC97_LINE1_LEVEL, 0);

	return 0;
}

/*
 * hw_free callback:
 * clean up the buffer description table and release the buffer
 */
static int snd_via82xx_hw_free(struct snd_pcm_substream *substream)
{
	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
	struct viadev *viadev = substream->runtime->private_data;

	clean_via_table(viadev, substream, chip->pci);
	snd_pcm_lib_free_pages(substream);
	return 0;
}


/*
 * set up the table pointer
 */
static void snd_via82xx_set_table_ptr(struct via82xx_modem *chip, struct viadev *viadev)
{
	snd_via82xx_codec_ready(chip, chip->ac97_secondary);
	outl((u32)viadev->table.addr, VIADEV_REG(viadev, OFFSET_TABLE_PTR));
	udelay(20);
	snd_via82xx_codec_ready(chip, chip->ac97_secondary);
}

/*
 * prepare callback for playback and capture
 */
static int snd_via82xx_pcm_prepare(struct snd_pcm_substream *substream)
{
	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
	struct viadev *viadev = substream->runtime->private_data;

	snd_via82xx_channel_reset(chip, viadev);
	/* this must be set after channel_reset */
	snd_via82xx_set_table_ptr(chip, viadev);
	outb(VIA_REG_TYPE_AUTOSTART|VIA_REG_TYPE_INT_EOL|VIA_REG_TYPE_INT_FLAG,
	     VIADEV_REG(viadev, OFFSET_TYPE));
	return 0;
}

/*
 * pcm hardware definition, identical for both playback and capture
 */
static struct snd_pcm_hardware snd_via82xx_hw =
{
	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
				 SNDRV_PCM_INFO_MMAP_VALID |
				 /* SNDRV_PCM_INFO_RESUME | */
				 SNDRV_PCM_INFO_PAUSE),
	.formats =		SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
	.rates =		SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_KNOT,
	.rate_min =		8000,
	.rate_max =		16000,
	.channels_min =		1,
	.channels_max =		1,
	.buffer_bytes_max =	128 * 1024,
	.period_bytes_min =	32,
	.period_bytes_max =	128 * 1024,
	.periods_min =		2,
	.periods_max =		VIA_TABLE_SIZE / 2,
	.fifo_size =		0,
};


/*
 * open callback skeleton
 */
static int snd_via82xx_modem_pcm_open(struct via82xx_modem *chip, struct viadev *viadev,
				      struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;
        static unsigned int rates[] = { 8000,  9600, 12000, 16000 };
        static struct snd_pcm_hw_constraint_list hw_constraints_rates = {
                .count = ARRAY_SIZE(rates),
                .list = rates,
                .mask = 0,
        };

	runtime->hw = snd_via82xx_hw;
	
        if ((err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
					      &hw_constraints_rates)) < 0)
                return err;

	/* we may remove following constaint when we modify table entries
	   in interrupt */
	if ((err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS)) < 0)
		return err;

	runtime->private_data = viadev;
	viadev->substream = substream;

	return 0;
}


/*
 * open callback for playback
 */
static int snd_via82xx_playback_open(struct snd_pcm_substream *substream)
{
	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
	struct viadev *viadev = &chip->devs[chip->playback_devno + substream->number];

	return snd_via82xx_modem_pcm_open(chip, viadev, substream);
}

/*
 * open callback for capture
 */
static int snd_via82xx_capture_open(struct snd_pcm_substream *substream)
{
	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
	struct viadev *viadev = &chip->devs[chip->capture_devno + substream->pcm->device];

	return snd_via82xx_modem_pcm_open(chip, viadev, substream);
}

/*
 * close callback
 */
static int snd_via82xx_pcm_close(struct snd_pcm_substream *substream)
{
	struct viadev *viadev = substream->runtime->private_data;

	viadev->substream = NULL;
	return 0;
}


/* via686 playback callbacks */
static struct snd_pcm_ops snd_via686_playback_ops = {
	.open =		snd_via82xx_playback_open,
	.close =	snd_via82xx_pcm_close,
	.ioctl =	snd_pcm_lib_ioctl,
	.hw_params =	snd_via82xx_hw_params,
	.hw_free =	snd_via82xx_hw_free,
	.prepare =	snd_via82xx_pcm_prepare,
	.trigger =	snd_via82xx_pcm_trigger,
	.pointer =	snd_via686_pcm_pointer,
	.page =		snd_pcm_sgbuf_ops_page,
};

/* via686 capture callbacks */
static struct snd_pcm_ops snd_via686_capture_ops = {
	.open =		snd_via82xx_capture_open,
	.close =	snd_via82xx_pcm_close,
	.ioctl =	snd_pcm_lib_ioctl,
	.hw_params =	snd_via82xx_hw_params,
	.hw_free =	snd_via82xx_hw_free,
	.prepare =	snd_via82xx_pcm_prepare,
	.trigger =	snd_via82xx_pcm_trigger,
	.pointer =	snd_via686_pcm_pointer,
	.page =		snd_pcm_sgbuf_ops_page,
};


static void init_viadev(struct via82xx_modem *chip, int idx, unsigned int reg_offset,
			int direction)
{
	chip->devs[idx].reg_offset = reg_offset;
	chip->devs[idx].direction = direction;
	chip->devs[idx].port = chip->port + reg_offset;
}